/* adlist.c - A generic doubly linked list implementation
*
* Copyright (c) 2006-2010, Salvatore Sanfilippo <antirez at gmail dot com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of Redis nor the names of its contributors may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <hiredis/alloc.h>
#include <stdlib.h>
#include "adlist.h"
#include "hiutil.h"
/* Create a new list. The created list can be freed with
* AlFreeList(), but private value of every node need to be freed
* by the user before to call AlFreeList().
*
* On error, NULL is returned. Otherwise the pointer to the new list. */
hilist *listCreate(
void
) {
struct
hilist *list;
if
((list = hi_malloc(
sizeof
(*list))) == NULL)
return
NULL;
list->head = list->tail = NULL;
list->len = 0;
list->dup = NULL;
list->
free
= NULL;
list->match = NULL;
return
list;
}
/* Free the whole list.
*
* This function can't fail. */
void
listRelease(hilist *list) {
unsigned
long
len;
listNode *current, *next;
current = list->head;
len = list->len;
while
(len--) {
next = current->next;
if
(list->
free
)
list->
free
(current->value);
hi_free(current);
current = next;
}
hi_free(list);
}
/* Add a new node to the list, to head, containing the specified 'value'
* pointer as value.
*
* On error, NULL is returned and no operation is performed (i.e. the
* list remains unaltered).
* On success the 'list' pointer you pass to the function is returned. */
hilist *listAddNodeHead(hilist *list,
void
*value) {
listNode *node;
if
((node = hi_malloc(
sizeof
(*node))) == NULL)
return
NULL;
node->value = value;
if
(list->len == 0) {
list->head = list->tail = node;
node->prev = node->next = NULL;
}
else
{
node->prev = NULL;
node->next = list->head;
list->head->prev = node;
list->head = node;
}
list->len++;
return
list;
}
/* Add a new node to the list, to tail, containing the specified 'value'
* pointer as value.
*
* On error, NULL is returned and no operation is performed (i.e. the
* list remains unaltered).
* On success the 'list' pointer you pass to the function is returned. */
hilist *listAddNodeTail(hilist *list,
void
*value) {
listNode *node;
if
((node = hi_malloc(
sizeof
(*node))) == NULL)
return
NULL;
node->value = value;
if
(list->len == 0) {
list->head = list->tail = node;
node->prev = node->next = NULL;
}
else
{
node->prev = list->tail;
node->next = NULL;
list->tail->next = node;
list->tail = node;
}
list->len++;
return
list;
}
hilist *listInsertNode(hilist *list, listNode *old_node,
void
*value,
int
after) {
listNode *node;
if
((node = hi_malloc(
sizeof
(*node))) == NULL)
return
NULL;
node->value = value;
if
(after) {
node->prev = old_node;
node->next = old_node->next;
if
(list->tail == old_node) {
list->tail = node;
}
}
else
{
node->next = old_node;
node->prev = old_node->prev;
if
(list->head == old_node) {
list->head = node;
}
}
if
(node->prev != NULL) {
node->prev->next = node;
}
if
(node->next != NULL) {
node->next->prev = node;
}
list->len++;
return
list;
}
/* Remove the specified node from the specified list.
* It's up to the caller to free the private value of the node.
*
* This function can't fail. */
void
listDelNode(hilist *list, listNode *node) {
if
(node->prev)
node->prev->next = node->next;
else
list->head = node->next;
if
(node->next)
node->next->prev = node->prev;
else
list->tail = node->prev;
if
(list->
free
)
list->
free
(node->value);
hi_free(node);
list->len--;
}
/* Returns a list iterator 'iter'. After the initialization every
* call to listNext() will return the next element of the list.
*
* This function can't fail. */
listIter *listGetIterator(hilist *list,
int
direction) {
listIter *iter;
if
((iter = hi_malloc(
sizeof
(*iter))) == NULL)
return
NULL;
if
(direction == AL_START_HEAD)
iter->next = list->head;
else
iter->next = list->tail;
iter->direction = direction;
return
iter;
}
/* Release the iterator memory */
void
listReleaseIterator(listIter *iter) { hi_free(iter); }
/* Create an iterator in the list private iterator structure */
void
listRewind(hilist *list, listIter *li) {
li->next = list->head;
li->direction = AL_START_HEAD;
}
void
listRewindTail(hilist *list, listIter *li) {
li->next = list->tail;
li->direction = AL_START_TAIL;
}
/* Return the next element of an iterator.
* It's valid to remove the currently returned element using
* listDelNode(), but not to remove other elements.
*
* The function returns a pointer to the next element of the list,
* or NULL if there are no more elements, so the classical usage patter
* is:
*
* iter = listGetIterator(list,<direction>);
* while ((node = listNext(iter)) != NULL) {
* doSomethingWith(listNodeValue(node));
* }
*
* */
listNode *listNext(listIter *iter) {
listNode *current = iter->next;
if
(current != NULL) {
if
(iter->direction == AL_START_HEAD)
iter->next = current->next;
else
iter->next = current->prev;
}
return
current;
}
/* Duplicate the whole list. On out of memory NULL is returned.
* On success a copy of the original list is returned.
*
* The 'Dup' method set with listSetDupMethod() function is used
* to copy the node value. Otherwise the same pointer value of
* the original node is used as value of the copied node.
*
* The original list both on success or error is never modified. */
hilist *listDup(hilist *orig) {
hilist *copy;
listIter iter;
listNode *node;
if
((copy = listCreate()) == NULL)
return
NULL;
copy->dup = orig->dup;
copy->
free
= orig->
free
;
copy->match = orig->match;
listRewind(orig, &iter);
while
((node = listNext(&iter)) != NULL) {
void
*value;
if
(copy->dup) {
value = copy->dup(node->value);
if
(value == NULL) {
listRelease(copy);
return
NULL;
}
}
else
value = node->value;
if
(listAddNodeTail(copy, value) == NULL) {
listRelease(copy);
return
NULL;
}
}
return
copy;
}
/* Search the list for a node matching a given key.
* The match is performed using the 'match' method
* set with listSetMatchMethod(). If no 'match' method
* is set, the 'value' pointer of every node is directly
* compared with the 'key' pointer.
*
* On success the first matching node pointer is returned
* (search starts from head). If no matching node exists
* NULL is returned. */
listNode *listSearchKey(hilist *list,
void
*key) {
listIter iter;
listNode *node;
listRewind(list, &iter);
while
((node = listNext(&iter)) != NULL) {
if
(list->match) {
if
(list->match(node->value, key)) {
return
node;
}
}
else
{
if
(key == node->value) {
return
node;
}
}
}
return
NULL;
}
/* Return the element at the specified zero-based index
* where 0 is the head, 1 is the element next to head
* and so on. Negative integers are used in order to count
* from the tail, -1 is the last element, -2 the penultimate
* and so on. If the index is out of range NULL is returned. */
listNode *listIndex(hilist *list,
long
index) {
listNode *n;
if
(index < 0) {
index = (-index) - 1;
n = list->tail;
while
(index-- && n)
n = n->prev;
}
else
{
n = list->head;
while
(index-- && n)
n = n->next;
}
return
n;
}
/* Rotate the list removing the tail node and inserting it to the head. */
void
listRotate(hilist *list) {
listNode *tail = list->tail;
if
(listLength(list) <= 1)
return
;
/* Detach current tail */
list->tail = tail->prev;
list->tail->next = NULL;
/* Move it as head */
list->head->prev = tail;
tail->prev = NULL;
tail->next = list->head;
list->head = tail;
}